This invention relates generally to cooling chambers, and, more particularly, to a Dewar cooling chamber which is capable of mounting semiconductor platelets therein for movement in three dimensions while maintaining the semiconductor crystal at a low temperature.
In recent years the use of semiconductor devices has expanded greatly. An area of particular interest involving semiconductors is the optically pumped semiconductor laser. In fact, recent advances in laser research have led to the development by the inventors of optically pumped semiconductor lasers which incorporate therein an external resonant cavity. Of particular interest are such lasers as described in U.S. patent application Ser. No. 361,021 entitled "Tunable CW Semiconductor Platelet Laser" and U.S. patent application Ser. No. 361,019 entitled "Synchronously Pumped Mode-Locked Semiconductor Laser", both applications being filed together with this patent application by the present inventors.
As clearly pointed out in the above-mentioned U.S. patent applications Ser. No. 361,021 and Ser. No. 361,019, in order to provide optimun outputs, the semiconductor platelets must be cooled to liquid nitrogen temperatures or below. In addition, a threshold of approximately 100 KW/cm.sup.2 requires an extremely tight beam focus for CW or quasi-CW lasing because the total power demanded by a larger spot size would be sufficient to destroy the semiconductor crystal. Furthermore, a small spot size is also required to eliminate amplified spontaneous emission. Therefore, it becomes essential to provide a mounting arrangement for the semiconductor crystal which not only allows for precise alignment of the crystal, but also provides sufficient cooling of the crystal to take place.